CLS

Action

Clear the LCD display and set the cursor to home.

 

 

Syntax

CLS

 

 

Syntax for graphical LCD

CLS

CLS TEXT

CLS GRAPH

CLS Y, X1 , X2  [, CHAR]

 

 

 

Remarks

Clearing the LCD display does not clear the CG-RAM in which the custom characters are stored.

For graphical LCD displays CLS will clear both the text and the graphical display.

The EADOG128 and KS108 support the option to clear a portion of a line. Depending on the used graphic chip, this option might be added to other  graphical LCD lib's too.

Graphical displays coordinates start with 1. To clear the entire first line you need to code : CLS 1,1,128

This will clear the first line, from the starting position X1(1) to the ending position(X2). You may specify an optional character to use. By default 0 is used. When you have inverse text, you need to use 255.

 

 

See also

$LCD , $LCDRS , LCD , SHIFTLCD , SHIFTCURSOR , INITLCD

 

 

Example

'-----------------------------------------------------------------------------------------
'name : lcd.bas
'copyright : (c) 1995-2005, MCS Electronics
'purpose : demo: LCD, CLS, LOWERLINE, SHIFTLCD, SHIFTCURSOR, HOME
' CURSOR, DISPLAY
'micro : Mega8515
'suited for demo : yes
'commercial addon needed : no
'-----------------------------------------------------------------------------------------
 
$regfile = "m8515.dat" ' specify the used micro
$crystal = 4000000 ' used crystal frequency
$baud = 19200 ' use baud rate
$hwstack = 32 ' default use 32 for the hardware stack
$swstack = 10 ' default use 10 for the SW stack
$framesize = 40 ' default use 40 for the frame space
 
 
$sim
'REMOVE the above command for the real program !!
'$sim is used for faster simulation
 
 
'note : tested in PIN mode with 4-bit
 
'Config Lcdpin = Pin , Db4 = Portb.1 , Db5 = Portb.2 , Db6 = Portb.3 , Db7 = Portb.4 , E = Portb.5 , Rs = Portb.6
Config Lcdpin = Pin , Db4 = Porta.4 , Db5 = Porta.5 , Db6 = Porta.6 , Db7 = Porta.7 , E = Portc.7 , Rs = Portc.6
'These settings are for the STK200 in PIN mode
'Connect only DB4 to DB7 of the LCD to the LCD connector of the STK D4-D7
'Connect the E-line of the LCD to A15 (PORTC.7) and NOT to the E line of the LCD connector
'Connect the RS, V0, GND and =5V of the LCD to the STK LCD connector
 
Rem with the config lcdpin statement you can override the compiler settings
 
 
Dim A As Byte
Config Lcd = 16 * 2 'configure lcd screen
 
 
'other options are 16 * 4 and 20 * 4, 20 * 2 , 16 * 1a
'When you dont include this option 16 * 2 is assumed
'16 * 1a is intended for 16 character displays with split addresses over 2 lines
 
'$LCD = address will turn LCD into 8-bit databus mode
' use this with uP with external RAM and/or ROM
' because it aint need the port pins !
 
Cls 'clear the LCD display
Lcd "Hello world." 'display this at the top line
Wait 1
Lowerline 'select the lower line
Wait 1
Lcd "Shift this." 'display this at the lower line
Wait 1
For A = 1 To 10
Shiftlcd Right 'shift the text to the right
Wait 1 'wait a moment
Next
 
For A = 1 To 10
Shiftlcd Left 'shift the text to the left
Wait 1 'wait a moment
Next
 
Locate 2 , 1 'set cursor position
Lcd "*" 'display this
Wait 1 'wait a moment
 
Shiftcursor Right 'shift the cursor
Lcd "@" 'display this
Wait 1 'wait a moment
 
Home Upper 'select line 1 and return home
Lcd "Replaced." 'replace the text
Wait 1 'wait a moment
 
Cursor Off Noblink 'hide cursor
Wait 1 'wait a moment
Cursor On Blink 'show cursor
Wait 1 'wait a moment
Display Off 'turn display off
Wait 1 'wait a moment
Display On 'turn display on
'-----------------NEW support for 4-line LCD------
Thirdline
Lcd "Line 3"
Fourthline
Lcd "Line 4"
Home Third 'goto home on line three
Home Fourth
Home F 'first letteer also works
Locate 4 , 1 : Lcd "Line 4"
Wait 1
 
'Now lets build a special character
'the first number is the characternumber (0-7)
'The other numbers are the rowvalues
'Use the LCD tool to insert this line
 
Deflcdchar 1 , 225 , 227 , 226 , 226 , 226 , 242 , 234 , 228 ' replace ? with number (0-7)
Deflcdchar 0 , 240 , 224 , 224 , 255 , 254 , 252 , 248 , 240 ' replace ? with number (0-7)
Cls 'select data RAM
Rem it is important that a CLS is following the deflcdchar statements because it will set the controller back in datamode
Lcd Chr(0) ; Chr(1) 'print the special character
 
'----------------- Now use an internal routine ------------
_temp1 = 1 'value into ACC
!rCall _write_lcd 'put it on LCD
End

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